The following approach demonstrates how you can stroll displayed web page (document) at specified position using JavaScript:  

import com.teamdev.jxbrowser.chromium.Browser;
import com.teamdev.jxbrowser.chromium.events.FinishLoadingEvent;
import com.teamdev.jxbrowser.chromium.events.LoadAdapter;
import com.teamdev.jxbrowser.chromium.swing.BrowserView;

import javax.swing.*;
import java.awt.*;

/**
 * This sample demonstrates how to scroll document programmatically.
 */
public class ScrollDocumentSample {
    public static void main(String[] args) {
        Browser browser = new Browser();
        BrowserView view = new BrowserView(browser);

        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        frame.add(view, BorderLayout.CENTER);
        frame.setSize(600, 500);
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);

        browser.addLoadListener(new LoadAdapter() {
            @Override
            public void onFinishLoadingFrame(FinishLoadingEvent event) {
                if (event.isMainFrame()) {
                    event.getBrowser().executeJavaScript(
                            "window.scrollTo(document.body.scrollWidth, " +
                            "document.body.scrollHeight);");
                }
            }
        });
        browser.loadURL("http://www.teamdev.com");
    }
}